Spindle oil composition



Unite States Patent SPHNDLE on COMPOSITION John N. Bowden, Crystal Lake, and Elmer W. Brennan, Carpentcrsvilie, llL, assignors to The Pure Oil Company, Chicago, M., a corporation of Ohio No Drawing. Application Jul 27, 1954 Serial No. 446,174,

4 Claims. (Cl. 252-412) This invention relates to an improved lubricating oil composition and more specifically to an improved lubricating oil composition which exhibits little or no corrosion of various metals and metal alloys and which is especially suitable for use as a spindle oil in the lubrication of textile machinery. a

Modern textile spinning frames commonly have 200 or more steel or "steel alloy spindles. The spinning operations of a modern textile mill ordinarilyconsume a large proportion, up to 40-60%, of the total power used in the mill. This is true whether the mill is devoted primarily to the processing of cotton, wool or synthetic fibers. Since the greatest portion of the power used in the spinning frame is devoted to the operation of the spinning frame spindles, proper lubrication of the spindles and spindle bearings effects great savings in power and renders textile operations more efiicient and less costly. Until recently, spindle oils have been mainly straight petroleum hydrocarbon oils of varying viscosities, and of a more or less highly refined nature. As textile operations have become more complex and spinning machinery is being operated at increasingly higher speeds for longer periods of time, the need for enhancing the effectiveness of spindle oils has become more acute, and in the last few years various additive agents have been added to spindle oils in order to produce spindle oil compositions which exhibit enhancement of such characteristics as the lubricity of spindle oils and their anti-corrosion properties. Such agents commonly impart advantageous qualities to the base oil or inhibit deleterious characteristics.

The characteristics of a modern spindle oil must be adjusted to meet the needs of modern types of spindles in use, each of which presents a slightly different lubrication problem. The Whitin plain bearing type, the Whitin SKF type, the Marquette roller bearing type and the Universal uniflex type, are examples of modern spindles used in textile mills. A suitable spindle oil composition should be able to satisfy the lubrication needs of each of these types of spindles. Whitin plain bearing spindles are very extensively used and commonly operate at speeds of 9,000 to 11,000 R. P. M. Such spindles require spindle oils of varying viscosities depending on operating conditions; about 60-220 secs. S. U. S. at 100 F. is the usual viscosity range for these spindles. The Whitin SKF spindle has a floating bolster and is similar to the Whitin plain bearing type, both requiring spindle oil which will satisfactorily cushion vibration inherent in the design. The Whitin SKF spindle has an anti-friction bearing so that an oil of low viscosity may be used. a

i In order to avoidunbalanced bobbin conditions and consequent power loss throughfrictional vibration, proper cushioning must be provided by the spindle oil. The cushioning effect of the oil and its lubricating ability are directly related to the viscosity of the oil whenan unfortified straight petroleum hydrocarbon oil is utilized as the spindle oil. The source. of the initial crude oil, that is, its content offparafiins, aromatics and the like, and the 2 degree and type of refining to which the crude has been subjected influence both the viscosity and certain other important characteristics of the oil. It has been found that refining petroleum hydrocarbon oil usually decreases the natural lubricity of the oil by removing certain naturally occurring oiliness agents from the oil. Usually in highly refined oils, the lower the viscosity of the oil, the lower the lubricity of the oil and its cushioning effect. A. desirable spindle oil should, however, be of the lowest viscosity consonant with high oiliness, high film strength and satisfactory cushioning effect because the internal friction of a spindle is increased by the use of a spindle oil of increased viscosity and an increase in internal friction of the spindle causes increased power loss. The film strength of the oil should be high in order to maintain at all times an adhesive, protecting, lubricating film over the surface of the moving spindle parts, thereby reducing friction and wear. Increased high film strength is also advantageous where the structure of the spinning frame and spindles increases the likelihood of escape of oil from the oil bath or from movable parts by splashing or dripping. Losses of textiles would be high, since oil ordinarily stains fabrics.

In the Marquette roller bearing type of spindle, an antifriction bearing is provided and vibration is so small that the need for carefully regulating the viscosity in order to obtain satisfactory cushioning is less. Consequently, lower viscosity spindle oil may be utilized in this type of spindle, lubricity being the prime consideration. The speed and length of operation of the spindle have little influence on the choice of oil, a single oil for all operations usually being satisfactory.

The Universal uniflex spindle has both a roller bearing operating with little frictional vibration at the top of the spindle case, and a plain, fixed footstep bearing which introduces to a smaller extent than in the Whitin plain bearing type of spindle the problem of cushioning vibration.

Certain types of textile machinery other than spinning frames are lubricated in mills with spindle oils. For example, card comb boxes, operating at 9001500 R. P. M., are lubricated by soaking felt at infrequent intervals, sometimes only once a year, with spindle or other types of oil, in contrast to the oil bath at the bottom of the spinning machine spindle and adjacent to the spindle bearing. In the oil-soaked felt type of lubrication, the loss of lubricant is very low, and because the lubricant is utilized over an extremely long period of time, the necessity for the lubricant to exhibit good oxidation resistance is increased. An ideal spindle oil, however, whether used with a soaked-felt type of operation or in an oil bath must incorporate oxidation resistance and resistance to decomposition and breakdown over a wide range of operation conditions. This is particularly true since the average textile mill may contain from 200,000 to over 1,000,000 spindles, and a large number of other types of machinery requiring lubrication. The problem of servicing such a vast number of spindles and other machinery is necessarily great, and a stable spindle oil reduces servicing and repair of spindles. Resistance to breakdown and formation of gummy materials is particularly important in spindle oils since any formation of gummy ning frames may also aid'rusting. Oil oxidation and.

Pierced A r--15, 5

heat decomposition products are frequently corrosive in nature and may attack steel. An anti-oxidant is therefore necessary in a suitable spindle oil to prevent the formation of gummy and corrosive substances; an antirust agent in the spindle oil is also necessary in order to furnish adequate protection for the steel spindles and other textile machine parts lubricated by spindle oils.

An ideal spindle oil also should incorporate mild extreme pressure characteristics, since modern spindles operate at speeds of 6000 to 20,000 R. P. M. and pressure conditions may develop in the oil between the bearing and the spindle proper, leading to a breakdown of the oil film unless protected by a suitable extreme pressure component. Future spindle speeds probably will be even higher than at present and will oifer greater pressure problems.

It therefore appears that an ideal spindle oil should have stability in order to prevent breakdown due to operating conditions or to oxidation of the oil, and to prevent the formation of gummy substances which not only clog the operation of the machinery but increase the viscosity and power loss due to friction. The ideal spindle oil also should have corrosion resistance to protect the steel or iron alloy surface of the spindle from corrosive decomposition products and an adverse environment. Furthermore, the oil should exhibit mild extreme pressure characteristics to protect equipment during fast spinning operations; increased oiliness and film strength also are desired together with as low a viscosity as is suitable.

Accordingly, it is an object of this invention to provide an improved spindle oil which is suitable for use under a variety of operating conditions and has improved loadcarrying properties. It is another object of this invention to provide a lubricating oil composition which exhibits suitable load-bearing characteristics, lubricity, and resistance to oxidation and rusting. It is still another object of this invention to provide a lubricant which exhibits a synergistic effect and cooperation between the oiliness agent and its anti-oxidant. It is a further object of this invention to provide a mineral lubricating oil composition, suitable for use as a spindle oil for textile operations, which exhibits unexpectedly increased loadbearing properties as the result of the synergistic action between an oiliness agent and an anti-oxidant incorporated. therein.

In general, this invention covers an improved lubricant incorporating an anti-oxidant, a rust inhibitor and an oiliness agent. More particularly, this invention relates to a lubricant for use as a spindle oil composition in the textile industry which comprises a major amount of a mineral oil and minor proportions of rust inhibitor, an oiliness agent and an anti-oxidant, the latter two of which act synergistically and cooperatively to increase unexpectedly the load-hearing characteristics of the composition.

The first constituent of the present composition is an.

oil, utilized as the base oil and present as the major proportion of the spindle oil composition. The oil may be any mineral oil which when combined with the additives above enumerated has suitable viscosity for the final spindle oil composition. The oil may be a petroleum hydrocarbon oil more or less highly refined. The more highly refined the oil utilized in the spindle oil composition, ordinarily the more corrosive to metals it will be, but the corrosiveness of the oil is offset by the anti-oxidant and the rust inhibitor of the spindle oil composition. The base oil may contain distilled or residual oil, but a neutral oil of approximately 85 viscosity is preferred. Other suitable hydrocarbon petroleum oils .re neutral oils of 100 viscosity and 170 viscosity.

The oiliness agent utilized in the composition of this invention is an ester of a lower monoor di-hydroxy aliphatic alcohol, such as methyl or ethyl alcohol, with a higher fatty acid, such as ricinoleic acid. By lower monohydroxy or dihydroxy aliphatic alcohol is meant a monohydroxy or dihydroxy aliphatic alcohol of a small number of carbon atoms, preferably 5 or fewer carbon atoms. For example, butyl alcohol and propyl alcohol, as well as glycol, are suitable for use in the preparation of the ester oiliness agent. Similarly, hydroxy fatty acids of a relatively large number of carbon atoms, such as, for example, hydroxy stearic acid, are suitable for use as the acid constituent in the preparation of the ester. A preferred ester oiliness agent is methyl ricinoleate. The usual methods of preparation of esters from fatty acids and alcohols are employed in the preparation of methyl 'ricinoleate and similar esters of lower aliphatic alcohols andhigher hydroxy fatty acids utilized in this invention. The ester is present in the spindle oil composition in an amount of at least 0.3 percent by weight and is preferably used in the composition in amount of 0.5 percent by weight.

The rust inhibitor used in the spindle oil composition of this invention may be any suitable rust inhibitor, such as a sodium sulfonatc, an ester of naphthenic acid, a metal soap of a fatty acid or a metal naphthenate. A suitable rust inhibitor which is particularly eifective in the spindle oil composition of this invention is zincnaphthenate. Other siutable rust inhibitors are the following: Victalube 5810, described by the supplier as an organic phosphate; Priminox 43, a reaction product of tcrtiary-alkyl primary amines and ethylene oxide, with the following general formula The rust inhibitor is present in the spindle oil composition in any amount sufficient to impart the desired rust inhibiting qualities to the spindle oil. In the case of zinc naphthenate 0.05 weight percent is used, and with certain other rust inhibitors as little as 0.002 weight percent may be adequate for the purposes of this invention. The anti-oxidant agent which is used in the spindle oil is designated as an aliphatic diamino substituted diaryl methane compound having the general structural formula where A and A represent amino groups, at least one and preferably both of which contain one or more aliphatic constituents, R and R are aromatic nuclei, and X and Y are either hydrogen or hydrocarbon groups. Typical members of this class of anti-oxidants are: p-amino p'-rnethylamino diphenylmethane; p,p'-di(methylamino) diphenylmethane; p-amino p -dimethylamino diphenylmethanc; p-methylamino p-di1nethylamino diphenylmethanc; tetramethyl-p,p-diamino diphenylmethane; p,p'-di(methylamino) di-o-tolyl methane; di(methylamino) dinaphthyl methane; p,p-di(methylamino) diphenyl methyl methane; p,p'-di(methylamino) diphenyl imethyl methane; p,p'-di(rnethylamin0) triphenyl methane; p,p'-di(methylamin0) tetraphenyl methane; p,pdi(methylamino) di(biphenyl) methane; tetramethyl p,p'-diamino triphenyl methane; tetramethyl p,p-diamino diphenyl dimethyl methane; and tetramethyl diamino dinaphthyl methane, as well as the corresponding compounds substituted in the ortho, meta or other positions, and compounds in which the methyl groups are replaced by other aliphatic groups such as ethyl, propyl, butyl, amyl, hexyl, heptyl, etc., either straight or branched chain. The anti-oxidant is present in the spindle oil composition in a minor amount sufficient to act synergistically with the oiliness agent so as to cause the loadbearing capacity of the oil composition to unexpectedly rise, and in amount sufiicient to protect the oil composition from oxidation. An amount such as 0.10 percent by weight, when the preferred anti-oxidant tetramethyl diamino diphenyl methane is used, is satisfactory.

Such other additivcsas usually appear in lubricating oils, that is, viscosity index improvers, pour depressants, detergents, anti-foam agents, extreme pressure additives and the like may be added to the spindle oil composition if desired. Typical detergents are aluminum naphthenates, calcium phenylstearates, calcium dichlorostearates, and calcium alcohol salicylates, alkaline earth metal petroleum sulfonates, synthetic sulfonated salts, alkaline earth metal alkyl phenol sulfides, metal salts of cetyl phenol, and metal salts of wax substituted phenol derivatives. Pour depressants such ar Paraflow, Santopour and Acryloid may be used, as well as other types. Paraflow is a complex condensation product of parafiin wax and naphthalene; Santopour has a similar composition, while Acryloid is a high molecular weight polymerization product of esters of methacrylic and similar acids and cetyl, lauryl and similar alcohols. Viscosity index improvers such as Paratone, a butene polymer, and Santodex, an alkyl styrene polymer, as well as other types may be-used. Anti-foam agents such as the silicone polymers (polymethyl'siloxanes) may be added to the composition of this invention if desired.

The synergistic action between the anti-oxidant and the lubricity agent or oiliness agent of the spindle oil composition incorporating the anti-oxidant and oiliness agent of this invention, together with a rust inhibitor,

was determined by a Timken test, Falex hour wear test and a Falex maximum load test.

The Faville-Le Vally lubricant testing machine (Falex machine) employs a small steel journal and two steel V- blocks as test pieces. The V-blocks are mounted in recesses in the loading arms of the machine in such a manner that they bear against opposite sides of the rotating journal. The load is applied to the arms by means of an auxiliary unit consisting of a ratchet wheel mounted on a threaded shaft which in turn is connected to a loading spring and a gage. When the machine is assembled, load is applied to the V-blocks by rotating the ratchet Wheel which, acting through the threaded shaft, introduces spring pressure on the loading arms. This force is indicated on the gage as load in pounds. Load can be applied either manually by rotating the ratchet wheel or automatically by engaging the pawl with the ratchet wheel. The pawl is actuated by an eccentric so that it moves the wheel one, tooth at a time at a uniform rate.

Since the entire loading arm assembly is free to rotate about the axis of the journal, the friction between the journal and .V-blocks is transmitted to the arms as a torque which is opposed by a hydraulic piston and cylinder. The resulting pressure is indicated by a gage as torque in pound-inches.

An oil cup containing the test sample is placed so that the journal and the V-shaped bearing blocks are completely immersed in the oil. The hour wear test is conducted with'the Falex machine at a constant load of 400 pounds for onehour. There is a break-in period of one minute at 150 pounds after which the load isincreased to 400 pounds with the loading arm, and the ratchet wheel is marked with a pencil. After one hour of operation the machine is shut 0E and the ratchet wheel is turned back to the original 400 pounds indicated load. The

wheel is again marked and the number of teeth between marks isrecorded as the teeth wear. Temperature of oil, torque, and load readings are made at five minute intervals to follow the progress of the test.

The Falex maximum load test employs the same apparatus used in the hour wear test. The machine is started with a 250 pound load and run for a one-minute break-in period. The load is then increased gradually with the load-applying arm until seizure or failure occurs. Readings of temperature and torque are made at 250 pound load increments, and the load causing seizure is recorded as the maximum load. The Falex lubricant testing machine is manufactured by the Faville-Le Vally Corporation of Chicago, Illinois, which supplies information on the machine and testing procedures.

The Timken extreme pressure test is described in ASTM Bulletin No. 181, page 45, published in April 1952. The Timken extreme pressure test machine consists essentially of a horizontal rigid spindle mounted in two substantial roller bearings and rotated through a belt drive at a constant speed of 400 R. P. M. A hardened steel test block is mounted upon knife-edge bearings which are designed to promote correct alignment and uniform pressure distribution between the test cup mounted on the rotating spindle and the block. The load lever is used to force the block upward against the test cup with a mechanical advantage of ten; that is, 1 pound placed in the notch at the end of the lever will exert a force of 10 pounds on the test block. The machine is provided with a onegallon lubricant reservoir, and piping allows gravity flow of the test lubricant over the test specimens. A scavenging pump in the base of the machine removes the used lubricant and returns it to the tank. The reservoir is fitted with an electric heater. The automatic loading system is so designed that the load is applied uniformly at a definite rate.

The Timken extreme pressure test is started with no load and the machine is run for a 30 second break-in period. The automatic loader is started and the load is applied at the rate of 2.6 lbs/sec. The test is continued for 10 minutes, then discontinued and the block examined for weld or seizure. If no seizure occurred, a new block surface and a new cup are installed in the machine, and a new test is started with an increment of 10 pounds added to the load. Additional tests are conducted with loads heavier by ten pound increments until seizure or failure occurs. Then five pounds are removed from the load andthe test re-run. If no seizure occurs, the load is recorded as the O. K. Load. If seizure occurs, the load five pounds lighter, is the passing weight. Increments of 3 pounds are employed when light loads. are involved.

The preferred spindle oil composition tested incorporatedmethyl ricinoleate as the oiliness agent, Aerolube MB, which is a commercial brand of tetramethyl diamino diphenyl methane, as the anti-oxidant, and a rust inhibitor, zinc naphthenate. Combinations of rust inhibitor and oiliness agent, rust inhibitor alone, oiliness agent alone, oiliness agent and anti-oxidant, anti-oxidant and rust inhibitor and anti-oxidant alone were tested, in each case the additive or additives blended in viscosity neutral petroleum oil.

TABLE I Falex hour wear test data Composition, Wt. Percent #1 #2 #3 #4 #6 #6 85 V15. Neutral Base Oil 99. 36 99. 40 99. 60 99. 95 99. 99. 45 Methyl Ricinoleate- 0. 50 0. 50 0. 50 0. 50 Aerolube MB 0. 10 0. 10 0. 10 Zinc Naphthenate 0. 05 0. 05 0. 05 it il h l l J 400 jaw load: 325 so F n d 111 F ii a 0a or r. s 2 a e a e m Torque 34 15. 5 Fa in 1 In 3 1n g gg Teeth wear 70 86 45 sec 20 sec TABLE '11 F urther test data Component #1 #7 Percent Percent 85 vls. neutral 011.. 99. 35 99.85 Aerolube MB 0.10 0. Zinc Naphthenate 0. 05 0. 05 Methyl Riciuoleate 0. 50

Fnlex tests Composition Timken O.K. lbs. I

Maximum load Teeth wear #1 25 1,025 (average) 70. j #7 8 825 (average) Beyond test limits.

The above test results on the spindle oil compositions show that when methyl ricinoleate was used as the sole additive to the 85 viscosity neutral oil, the Falex hour wear test could not be passed; the composition failed in 8 minutes. When Aerolube MB was used as the sole additive to the base oil in the preparation of the spindle oil composition, the Falex hour wear test also failed, as was the case when zinc naphthenate appeared as the sole additive in the spindle oil composition. When the lubricity agent, methyl ricinoleate, was used in the spindle oil composition together with the rust inhibitor, zinc naphthenate, the Falex hour wear test still could not be passed, failure again being noted in 8 minutes. However, when the lubricity agent was used in the spindle oil composition in a concentration of 0.50 weight percent together with 0.10 weight percent of the anti-oxidant, tetramethyl diamino diphenyl methane, the Falex hour wear test was passed, with a tooth wear of about 86 with a 400 lb. jaw load being observed. Similar results were obtained by the use of the anti-oxidant, the rust inhibitor, and the oiliness agent together in the spindle oil composition in 0.10 weight percent, 0.05 weight percent and 0.50 weight percent amounts, respectively. The unexpectedly satisfactory Falex hour wear test results when the oiliness agent was used in combination with the anti-oxidant, although each additive alone produced unsatisfactory results, demonstrate the existence of synergism between the anti-oxidant, Aerolube MB, and the lubricity agent, methyl ricinoleate. As aforementioned, increased loadbearing properties, such as exhibited by these compositions, are extremely important in the production of a highly satisfactory spindle oil. The mechanism of action of such cooperation and synergism in the spindle oil composition is unknown. Such synergism is exhibited between esters of lower alkanols and higher fatty acids and anti-oxidants of the aliphatic diamino substituted diaryl methane type. The spindle oil composition of this invention, particularly the preferred composition incorporating a lubricity additive, such as methyl ricinoleate, in combination with an anti-oxidant, such as tetramethyl diamino diphenyl methane, and a rust inhibitor, such as zinc naphthenate, not only exhibits the superior oiliness and film strength characteristics conducive to decreased power loss and decreased wear, but also shows stability towards oxidation and deterioration under spindle operation conditions, as well as rust inhibition. The necessary and highly advantageous extreme pressure characteristics which prevent deterioration of the oil at increased spindle speeds and reduce the tendency of the oil to increase in viscosity are provided by the synergistic cooperation of the lubricity agent and anti-oxidant additives of the composition.

A non-limited example of the composition of this invention is the following:

The lubricating oil composition disclosed is preferably utilized as a spindle oil composition but is not limited to such a use. The composition may find application wherever a lubricating oil having oxidation stability, rust inhibition, increased lubricity and mild extreme pressure properties is desirable, such as for an automobile motor lubricating oil and the like.

We claim:

1. A lubricating oil comprising a major amount of mineral lubricating oil containing not less than 0.3% by weight of methyl ricinoleate and tetramethyl diamino diphenyl methane in an amount to co-operate synergistically with said methyl ricinoleate to increase the load bearing capacity of said oil, the ratio of methyl ricinoleate to tetramethyl amino diphenyl methane being about 5:1.

2. A lubricating oil in accordance with claim 1 containing a rust-inhibiting amount of zinc naphthenate.

3. A mineral lubricating oil comprising a major amount of a hydrocarbon mineral oil and about 0.50 weight percent of methyl ricinoleate, about 0.10 weight percent of tetramethyl diamino diphenyl methane and about 0.05 weight percent of zinc naphthenate.

4. A mineral lubricating oil comprising a major amount of mineral oil, about 0.50 weight percent of methyl ricinoleate and about 0.10 weight percent of tetramethyl diamino diphenyl methane.

References Cited in the file of this patent UNITED STATES PATENTS 2,210,140 Colbeth- Aug. 6, 1940 2,332,825 'Zimmer Oct. 26, 1943 2,346,356 Burk Apr. 11, 1944 2,393,929 Parker Jan. 29, 1946 2,440,530 Yates Apr. 27, 1948 

1. A LUBRICATING OIL COMPRISING A MAJOR AMOUNT OF MINERAL LUBRICATING OIL CONTAINING NOT LESS THAN 0.3% BY WEIGHT OF METHYL RICINOLEATE AND TETRAMETHYL DIAMINO DIPHENYL METHANE IN AN AMOUNT TO CO-OPERATE SYNERGISTICALLY WITH SAID METHYL RICINOLEATE TO INCREASE THE LOAD BEARING CAPACITY OF SAID OIL, THE RAIO OF METHYL RICINOLEATE TO TETRAMETHYL AMINO DIPHENYL METHANE BEING ABOUT 5:1. 